Questions tagged [supernova]

Questions regarding stars which increase suddenly in energy output due to an explosion which ejected much of its mass.

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Nearby galaxy distances

Type Ia supernovae are extremely useful in measuring the distance of remote galaxies. It is known that type Ia supernovae always reach the same brilliance at their peak. Like Cepheid variables, they ...
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Missing supernovae in the Milky Way

Stars with more than 8-16 solar masses usually go supernova. These are OB stars, of which 0.2% currently exist in our galaxy. The average lifespan of said star ranges from 10 to 40 million years. So ...
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How loud would a supernova, kilonova, and hypernova be? [closed]

If we could hear the sounds of these explosions directly where it was happening, how loud would each of these events be?
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Were there any images of Sanduleak -69 202 (progenitor of SN1987A) before it exploded?

We all know about SN1987A, the closest observed supernova since Kepler's time. Its progenitor was Sanduleak -69 202, a magnitude 12 blue supergiant, catalogued in 1970. Were there any images of this ...
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Reproduce and plot myself from a paper with appropriate scripts and Fisher/Covariance matrixes

I would like to reproduce and plot myself the figure below. This plot, even it begins to date, is full of informations for me. The paper is located here : paper Suzuki et al. 2011 I have contacted ...
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Long-lived supernova remnants?

We cannot see the supernova remnant of the star that triggered the formation of the Sun and the Solar System, as the remnant dispersed and became mixed into the interstellar medium. So I am wondering, ...
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Why does this nucleogenesis table not label s and r-processes for all elements (not-labmade) past Fe?

I'm reviewing nucleogenenesis and came across the table below. I like it because it actually labels the s and r-process elements, but I became confused as to why the neutron capture processes begin at ...
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Uranium accumulating inside a White Dwarf?

A couple of days ago, there was news that "Some dead stars may harbor enough uranium to set off a thermonuclear bomb", which is basically a teaser for Actinide crystallization and fission ...
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How do black holes form from stars that go supernova

I know that the cores of stars with more than 20 times the mass of the Sun collapse into black holes at the end of the star’s life. However, as far as my understanding goes, stars with cores that ...
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How are shockwaves in a star that cause supernova created

I know that during the collapsing of a star 8 times the mass of the Sun at the end of its life, a shockwave is generated that blows the star up. However, I do not understand how it is exactly ...
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What would happen if a neutron star merged with a white dwarf?

We've heard of neutron star mergers and white dwarf mergers. But what would result in a neutron star merging with a white dwarf? Would there be a similar super/kilonova, are there any examples of it, ...
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Can a star be massive enough to go 'supernova' yet not be massive enough to leave behind a neutron star? Or, perhaps vice versa?

From what I understand, stars that explode as a supernova at the end of their lives become either a black hole or a neutron star, and less massive stars that do not explode become white dwarves, but......
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What percent of all stars that have lived (up to now) are stellar remnants?

According to this post, I found that about 90% of all stars are main sequence stars. So I am assuming that the other 10% consists of protostars, older giant stars, and stellar remnants. So I'm ...
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Have there been any confirmed PISN supernovae?

I did some research on pair-instability supernovae (PISN), and wondered if there have been any confirmed superluminous supernovae caused by a pair-instability. Are there any confirmed PISNs out there, ...
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The star that died and became the Crab Nebula and Crab Pulsar?

The supernova of this star was witnessed about 1 thousand years ago, and the star's remains are the Crab Nebula and Crab Pulsar. What is this no longer existent star called? How massive was this star? ...
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When a fast-moving star goes supernova, how will the resulting remnant evolve?

Let's take a massive star that has zero velocity. When this star goes supernova, the resulting supernova remnant will expand in a sphere. But, let's take a runaway star travelling at 200 km/s. I am ...
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Are any of the zodiac stars about to go supernova anytime soon?

I have read that Betelgeuse, known as Ardra in Hindu astrology, could go supernova. Are any of the zodiac stars or the stars of lunar mansions about to become a black hole or supernova?
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After a supernova, why don't new stars coalesce with higher heavier element content?

May be a beginner's question but I couldn't find the answer anywhere. Given a supernova event and the cloud left by it, why does a new star coalesce with a disproportionally higher hydrogen(and helium)...
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What's the safe distance from a hypernova?

Hypernovae are even rarer than supernovae, occuring in stars at more than 30 solar masses, destroying the star that goes hypernova. This post states a hypernova releases several million times more ...
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Can a supernova or a close passing star create a transient sun gravity focus “habitable zone”?

This question was inspired by the previous question Would a black hole passing next to a star create a deadly focal point due to gravitational lensing?. I understand, as gravity also acts on light, ...
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Stellar life cycle flow chart with mass conditions and time scales

I remember that in my nuclear astrophysics lecture a decade ago, our lecturer drew a large flow chart like diagram of stellar evolution in dependence of the mass of the star (in solar units) on the ...
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Where did the hydrogen come from in a type II supernova?

Type II supernovae have hydrogen. Where did the hydrogen come from if that is the first element used up in the star's life cycle? Also if our solar system was seeded from an ancient supernova where ...
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How big would the supernova when a neutron star collides with another neutron star? [closed]

If two neutrons stars that are orbiting were to collide, how big would the supernova explosion be? Would a new black hole or a new supernova remnant be formed?
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How long does it take for a white dwarf to undergo a type Ia supernova?

I read about white dwarfs and their relation to Type Ia supernovae, and I want to know how much time passes between when the white dwarf passes the Chandrasekhar limit and when the white dwarf ...
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Type II supernovae as a distance indicator

Could someone explain in brief exactly how type II supernovae could be used as distance indicators? as in simply the formulae used and how they are employed? I know there are certain methods based on ...
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What is the “shockwave” of a supernova?

A common notion is that supernovae create shock waves in interstellar gas, and can compress them to star forming densities. How is that shockwave transmitted? Is it by ejected (sublight) particles, or ...
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How do you know that the remnants of the explosion of a Star are of a Hypernova?

Some Background? There are many types of Supernovae that can be classified into the following categories :- (This list is available here.) Type 1A supernovae • Their spectra show very little hydrogen ...
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How can many stars be formed from the remains of one supernova?

A supernova is the explosion of a single star; so how is it that thousands of stars can "be born of" that one explosion (presumably only using the unspent fuel / lighter elements of the ...
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How many supernovae events are on their way from within the Milky Way?

The Milky Way has a diameter of around 100.000 light years with the Solar system placed some 25,000 light years from the center. If we assume a supernova rate of 1 per century, and also assume that ...
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Calculating Relative Abundances to Solar For Explosive Nucleosynthesis Yields

I am having trouble deriving the abundance ratios for the ejecta products of a given supernova explosion model. From the explosion models, we are given the mass of 3 isotopes of every element produced ...
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Did I see a supernova explosion?

I think I just saw a supernova explode with my own eyes through my GSO 12 inch Dobsonian. Please tell me what it was! I am still trying to find what it was it was mindblowing! I went out on my roof ...
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Would a naked eye supernova become a disc in a matter of days?

Stars are points of light even in telescopes- if they go supernova, their diameter does expand, but given the distance of even nearby stars, they would still be points of light, I suppose? I am asking ...
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What does “located in the Hubble flow” mean?

I do not understand that much about the term Hubble flow. For cosmological studies with type Ia supernova, I often see the sentence like "We used 100 SNe Ia in the Hubble flow". What does ...
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Why did supernova 1987A's “String of 'Cosmic Pearls'” appear to be so lumpy 20 years later? Is it still?

NASA's A String of 'Cosmic Pearls' surrounds an exploding star is beautiful and the page says: This image shows the entire region around the supernova. The most prominent feature in the image is a ...
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How can I estimate the initial luminosity of a SNIa given initial mass of Ni-56?

The initial portion (and peak) of a SNIa's light curve is powered by the $\beta$-decay reaction: $$ ^{56}Ni \rightarrow ^{56}Co + e^+ + \nu_e + \gamma $$ Supposing we know how much Ni-56 is created in ...
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At what distance could a supernova damage the Earth's ozone layer?

As from my latter question it seems Betelgeuse might be much closer than the usually presumed 640 light years. It might be as close as ~440 ly. Suppose it is, would this have any dangerous effects on ...
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Galactic winds/outflows: why and how are they detected via blueshifted absorption lines in spectra?

I know that galaxies can eject gas due to supernovae, accreting black holes, etc. These galactic "winds/outflows" are often defined/detected observationally using blueshifted absorption ...
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When was it worked out/discovered that our sun can't go supernova?

As the title says, when did we realise with reasonable confidence that our star is not going to be going out in a supernova blaze of glory? I ask because a while ago I read The Songs of Distant Earth ...
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What happens when a huge star is being consumed by a black hole

What happens when a huge star in its later stage( iron core) is near a black hole that slowly consumes some of the matter from the star? Would this offset the imbalance caused by iron fusion ...
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Why are there so few supernovae in M31 (Andromeda)?

Estimates of the supernova rate in the Milky Way put it at a few per century, but very few of these are visible from Earth (at least with the naked eye) because of intervening gas and dust clouds). On ...
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How often are supernovas visible by the naked eye from Earth?

I heard about the 1054 supernova that was visible with the naked eye. Of course, these events happen at random. But just like with radioactive decay, it must be possible to determine statistics on ...
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any proof that stars are born, and die?

I've heard from a lot of people that stars are "born" (usually from black holes), then grow bigger, then eventually "die" by some kind of supernova etc., but have any of these events actually been ...
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What kind of radiation do supernova remnants emit?

Do supernova remnants emit EM radiation? Moreover can neutrinos be emitted by these remnants?
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Why do pair production and photodisintegration have such different effects in collapsing supermassive stars?

Stars of at least 100 solar masses or so can reach core temperatures (and, thus, core photon energies) great enough that pair production (where a very-high-energy photon strikes another particle, ...
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Why don’t supergiants at least start to fuse nickel into even heavier elements before going supernova?

The last primary fusion process to take place in extremely massive stars is silicon burning, where the 28Si produced by oxygen burning is exothermically fused with alpha particle after alpha particle ...
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Was the “green star” event in NGC 3314 ever figured out or named?

from NGC 3314 Variable Object by By Bill Keel (University of Alabama, Tuscaloosa) and Lisa Frattare (Hubble Heritage Project, STScI). The object in question is circled. Comments below this answer led ...
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What causes fast moving pulsars to move so fast?

This article investigates the traces left in the ISM by fast moving pulsars. Is there a mechanism specific to pulsars that causes them to move so fast, or are there just as many fast moving stars? ...
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How does a supernova occur when a massive star collapses into a black hole?

My layman's understanding of a supernova explosion is that it's caused by a rebound when a massive star collapses. When the core collapses to a point where neutron degeneracy pressure dominates, the ...
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When Betelgeuse goes supernova, will the explosion hit any neighboring stars?

There is evidence Betelgeuse might go supernova "soon". Are there any stars in the vicinity of Betelgeuse that are close enough that they will be hit by the explosion of this supernova? What would be ...
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How scientists estimated the number of near-Earth supernovae over the last 11 million years?

According to this article on wikipedia, An estimated 20 supernova explosions have happened within 300 pc of the Earth over ...